scholarly journals Application of thermal analysis in ferrous and nonferrous foundries

10.30544/673 ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 457-471
Author(s):  
Mile B Djurdjevic
Keyword(s):  
Thermal Analysis ◽  
Sound Production ◽  
Solidification Process ◽  
Casting Process ◽  
Cooling Curve ◽  
Time Data ◽  
Iron And Steel ◽  
Steel Metallurgy ◽  
Analysis Application ◽  
Future Potential

This paper is devoted to the memory of Professor Ljubomir Nedeljkovic (1933-2020), Head of the Department of Iron and Steel Metallurgy University of Belgrade, Serbia. Assessment of the melt quality is one of the most important casting process parameters, which allowed sound production of intricated cast parts. At the present time, various devices have been applied at foundry floors to control melt quality. Thermal analysis is one of them, widely used for melt quality control in ferrous and non-ferrous casting plants. During solidification, metal and alloys released latent heat, which magnitude is dependent on the type of phases that form during the solidification process. Plotting temperature versus time data during solidification provides useful information related to the actual solidification process. The applied technique is called thermal analysis, whereas the cooling curve is the name of such a plot. The main aim of this paper is to give a short overview of the present thermal analysis application in various foundries and to indicate the future potential use of this technique.

Thermal Analysis to Optimize and Control the Cast Iron Solidification Process

2016 ◽  
Vol 254 ◽  
pp. 14-19 ◽  
Author(s):  
Iulian Riposan ◽  
Ion Stefan ◽  
Ciprian Firican ◽  
Stelian Stan
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Solidification Process ◽  
Cooling Curve ◽  
Specific Factor ◽  
Iron Carbides ◽  
Coreless Induction Furnace ◽  
Eutectic Undercooling ◽  
Solidification Parameters ◽  
Effect Ratio

The cooling curve and its derivatives display patterns that can be used to predict the characteristics of a cast iron. The effects of melting, superheating and holding in an acid lined coreless induction furnace were explored, as they affect the role of preconditioning and / or inoculation to restore solidification with low eutectic undercooling. Increased chill (iron carbides amount) in the experimental irons correlates well with certain thermal analysis parameters, such as the degree of eutectic undercooling. Preconditioning of the molten base iron before tapping led to improved solidification parameters in both untreated and inoculated irons as measured by the most significant thermal analysis cooling curve events. A double treatment incorporating preconditioning with inoculation improved the thermal analysis parameters, and consequently, the quality of the cast iron. If standard Ca-FeSi alloys do not have sufficient inoculation potential, the addition of the inoculant enhancing alloy (S, O and oxy-sulphides forming elements) will greatly enhance inoculation, well illustrated by changes to the thermal analysis parameters. A newly defined Inoculation Specific Factor [inoculation effect / inoculant consumption which led to that beneficial effect ratio] of different alloys is illustrated by thermal analysis, with good correlation with microstructural characteristics.

STUDY ON WET PROCESSING OF BLOCK CHILLY

2013 ◽  
Vol 3 (1) ◽  
pp. 45-50
Author(s):  
Dwi Dian Praptanto ◽  
Kurnia Herlina Dewi ◽  
Bosman Sidebang
Keyword(s):  
Water Content ◽  
Production Method ◽  
Time Data ◽  
Time Duration ◽  
Drying Time ◽  
Significance Level ◽  
Randomized Design ◽  
Wet Processing ◽  
Analysis Application ◽  
Lower Water Content

The purpose of this study is to examine the effect of drying time in weight and water content, combination effect of drying time and size of the material, and consumer acceptance to the product in the wet processing of chili blocks production. Method used in the research is completely randomized design (CRD) with two factorials are material size and drying time. Data were analyzed using ANOVA and further analysis using DMRT at 5% significance level. Organoleptic test result was analyzed using the Kruskal-Wallis and Tukey test for further analysis. Application of the equal drying time to two different size of material: rough and finest block chili, showed the result that water content of the rough block chili is lower than the finest block chilli. Application of the different drying time duration to the same size of chili showed the lower water content with increasing duration of drying time. The water content of the material tends to decrease with increasing duration of drying time. The level of consumer’s preferences to the product of wet processing of chili blocks production is equal for scents, but it’s different for color, texture and overall preferences.

scholarly journals Study of the Effect of Carbon on the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 982 ◽  
Author(s):  
Dazhi Pu ◽  
Guanghua Wen ◽  
Dachao Fu ◽  
Ping Tang ◽  
Junli Guo
Keyword(s):  
Surface Roughness ◽  
Cooling Rate ◽  
Solidification Process ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Peritectic Steel ◽  
Laser Confocal Microscope ◽  
Initial Solidification

In the continuous casting process, the shrinkage of the peritectic phase transition during the initial solidification process has an important influence on the surface quality of peritectic steel. The initial solidification process of 0.10C%, 0.14C%, and 0.16C% peritectic steels was observed in situ by a high temperature laser confocal microscope, and the contraction degree during initial solidification was characterized by surface roughness. The results showed that under the cooling rate of 20 °C/s, the surface roughness value Ra(δ/γ) of 0.10C% peritectic steel was 32 μm, the Ra(δ/γ) value of 0.14C% peritectic steel was 25 μm, and the Ra(δ/γ) value of 0.16C% peritectic steel was 17 μm. With increasing carbon content, the contraction degree of the δ→γ transformation decreased, and the value of the surface roughness Ra(δ/γ) declined. Therefore, surface roughness can characterize the contraction degree of the δ→γ transformation in the initial solidification process of peritectic steel under the condition of a large cooling rate.

Solidification Process, Microstructure, Density and Hardness of the Mg-Al Alloys with Zn, Cu, Ni and AlTiB Additions

2011 ◽  
Vol 176 ◽  
pp. 91-98
Author(s):  
Franciszek Binczyk
Keyword(s):  
Thermal Analysis ◽  
Regression Analysis ◽  
Operating Temperature ◽  
Solidification Process ◽  
Al Alloys ◽  
Pouring Temperature ◽  
Significance Level ◽  
Solidification Parameters ◽  
Microstructure Density

The paper presents the results of the investigations of the solidification process of magnesium alloys containing 5 and 10 wt.% Al, the additions of Zn, Cu, Ni, and of an AlTiB master alloy. The plotted DTA (derivative thermal analysis) curves were used for the determination of solidification parameters Tliq, Teut and Tsol. Knowledge of these parameters is very important in determination of alloy pouring temperature and maximum casting operating temperature. On samples taken from the area of temperature measurements, the chemical composition and microstructure were determined. The density and hardness HB were measured as well. Applying the method of multiple regression analysis at the significance level α = 0.1, the intensity and direction of the effect of alloying elements on the solidification parameters, density and hardness HB of castings were evaluated.

Thermal Analysis of Aluminum Alloys

2019 ◽  
Author(s):  
Daniel Larouche
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Quality Control ◽  
Aluminum Alloys ◽  
Isothermal Calorimetry ◽  
Curve Analysis ◽  
Cooling Curve ◽  
Scanning Calorimetry ◽  
Cooling Curve Analysis ◽  
Scientists And Engineers

Thermal analysis is applied on aluminum alloys by researchers to investigate mainly phase transformations, while it is regularly used for quality control purposes in industry. Techniques like cooling curve analysis, differential thermal analysis, differential scanning calorimetry, and isothermal calorimetry are amongst those most frequently used by scientists and engineers. These techniques will be described, and a mathematical description of the results will be developed. State-of-the-art quantification methods applied on aluminum alloys will be presented and criticized based on specific examples taken from the literature.

Melt Mold Casting Process Optimization of Train Coupler Based on ProCAST

2018 ◽  
Vol 764 ◽  
pp. 312-322
Author(s):  
Cheng Jun Wang ◽  
Jin Yan Chen ◽  
Yu Zhe Shen
Keyword(s):  
Process Optimization ◽  
Simulation Analysis ◽  
Solidification Process ◽  
Casting Process ◽  
Process Measures ◽  
Technical Requirements ◽  
Shrinkage Defects ◽  
Mold Casting ◽  
Cae Simulation ◽  
Filling And Solidification

In order to solve production defects such as shrinkage and porosity inside a certain train coupler casting in Anhui Xinhong Machinery Co.,Ltd., the main reasons of defects are found through the process of CAE simulation analysis and physical X ray detection to determine the location and morphology of casting defects and to reflect the actual situation of coupler filling and solidification process. The main reasons are found as follows: uneven thickness of casting structure, insufficient original gating and feeding system and etc. Through the process optimization and apply multidimensional vibration, then test validation, the train coupler casting which meets the technical requirements has been successfully produced, ensuring the smooth mass production of the company. ProCAST numerical simulation results have confirmed the rationality of the proposed work in optimization process measures in reducing and eliminating the shrinkage defects.

A Volume-of-Fluid Based Numerical Simulation of Solidification in Binary Alloys on Fixed Non-Uniform Co-Located Grids

2009 ◽  
Author(s):  
Mehdi Farrokhnejad ◽  
Anthony G. Straatman ◽  
Jeffrey T. Wood
Keyword(s):  
Volume Fraction ◽  
Binary Alloys ◽  
Solidification Process ◽  
Casting Process ◽  
Reconstruction Algorithm ◽  
Volume Of Fluid ◽  
Mold Filling ◽  
Mg Alloys ◽  
Uniform Grid ◽  
Spurious Currents

In this paper, the authors present a platform for the modeling of mold filling and solidification of binary alloys with properties similar to Mg alloys. A volume-of-fluid (VOF) based method is used to capture the interface between solid and liquid in binary alloys solidification process on a fixed non-uniform grid, developed for implementation in a colocated finite volume framework. Contrary to other works, to update the volume fraction (of fluid) in the field, a link between source-based type of energy equation and VOF reconstruction algorithm is described and implemented. A new approximation to the pressure gradient is presented to remove all ‘Spurious Currents’ [1] resulting from pressure jumps in the vicinity of the interface. Based upon the work presented, it is concluded that the present combination of the equations are not only computationally straightforward to implement and upgrade to a 3D problem, but also provides an excellent platform to capture the interface between constituents in a die-casting process including solidification and mold filling process. The current framework will be used in future works to characterize the local mechanical properties of Mg alloys by using information from simulation at the dendritic level.

Body Temperature and Singing in the Bladder Cicada, Cystosoma Saundersii

1979 ◽  
Vol 80 (1) ◽  
pp. 69-81 ◽  
Author(s):  
R. K. JOSEPHSON ◽  
D. YOUNG
Keyword(s):  
Heat Production ◽  
Cell Biology ◽  
Sound Production ◽  
Marked Decrease ◽  
Cooling Curve ◽  
Muscle Twitch ◽  
Temperature Excess ◽  
Air Mixing ◽  
Artificial Heat ◽  
Sound Pulses

1. Body temperatures during singing were measured in the cicada, Cystosoma saundersii Westwood, both in the field and in tethered animals indoors. 2. The temperature of the sound-producing tymbal muscle rises rapidly during singing to reach a plateau approximately 12°C above ambient. This produces a temperature gradient in the abdominal air sac which surrounds the muscle. When singing stops, the tymbal muscle cools exponentially. 3. Heat production during singing, estimated from the cooling curve, is 4.82 cal min−1 g muscle−1. Generation of the same temperature excess in the air sac by an artificial heat source yields an estimated heat production of 54.4 cal min−1 g muscle−1. This discrepancy may be caused by air mixing in the air sac during singing. 4. As temperature rises, tymbal muscle twitch contractions become faster and stronger. This and heat transfer to the thorax cause changes in the song pattern: a marked decrease in the interval between the two sound pulses produced by a single tymbal buckling and a lesser decrease in the interval between bucklings. The fundamental sound period remains unaltered. These effects are consistent with earlier data on sound production. Note: Present address: Department of Developmental and Cell Biology, University of California, Irvine, California 92717, U.S.A.

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